Severn Estuary Special Area of Conservation (SAC) and Special Protection Area (SPA): Intertidal Mudflats and Sandflats Condition Assessment 2012
The Severn Estuary is the largest example of a coastal plain estuary in the United Kingdom. It has been designated as a Special Area of Conservation (SAC) under the EU Habitats Directive, a Special Protection Area (SPA) under the Birds Directive and as a Ramsar site under the Convention on Wetlands of International Importance.
The primary focus of this study relates to monitoring the intertidal mudflats and sandflats feature of the Severn Estuary SAC by assessing the relevant attributes for the purpose of condition assessment. However, monitoring of prey availability within the Severn Estuary SPA was also a secondary objective.
The survey was undertaken in three blocks between the 13th October and 14th November 2012.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS115547
- Alternative Title
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- MRNE013700000005 - Severn Estuary SAC Sandflat and Mudflat Condition Assessment 2012
- Severn Estuary SAC Sandflat and Mudflat Condition Assessment 2012
- Metadata Language
- English
- Lineage
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The methods employed within this study were largely limited to Phase II sampling that was based on Phase I biotope maps from previous studies. However, if any obviously incorrect biotope boundaries were encountered or if any notable habitats or species were observed during the course of the surveys, then records were appropriately amended. Anthropogenic influences and negative indicators were also recorded where encountered.
A total of 9 littoral mudflat and sandflat sediment biotopes were identified throughout the Severn Estuary SAC and SPA during the course of the study, and their subsequent extent and distribution was mapped using GIS. At each station;
- five replicate 0.01m2 cores were taken to a depth of 15 cm following ISI, Environment Agency and JNCC guidelines. A photograph of the sediment at the station and the general area was also taken. Macrofauna samples were delivered to APEM Ltd for analysis.
- the depth of the Redox Potential Discontinuity (RPD) layer was determined at each station and a second core taken for sediment granulometry. The sediment samples were delivered to the National Laboratory Service (NLS) at Starcross for PSA.
Previous Phase 1 biotope surveys were carried out on behalf of Natural England in 2005. Phase I surveys were also carried out on the Welsh shores between 1996 and 2005 on behalf of CCW. The specific methods used during these surveys are unknown as only the GIS map outputs are available.
- Additional Information
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Natural England, CCW and Environment Agency Wales (now NRW) jointly funded a joint sediment survey of the Severn estuary in 2012. The work was done as part of a framework agreement. CCW (now NRW) are free to supply Welsh related data.
- Dataset Reference Date (Publication)
- 2014-12-31
Extent
Extent
- Geographic Extent
- Wales (WLS)
))
Vertical Extent
- Medin Extent Keyword
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benthic boundary layer
Distribution
- Format Type and Description
-
-
Documents
(
)
- Specification
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[A] Report in .doc and .PDF format. To be published as a CCW report [B] Marine Recorder data files (provided as part of NE snapshot) although they have also provided a copy of their full mdb file. MRNE013700000005 - Severn Estuary SAC Sandflat and Mudflat Condition Assessment 2012 [C] Photos site and substrata for each station in .jpg format [D] Macrofauna analysis, PSA and raw data in xls format [E] GIS data in native ArcGIS format (shp) and tranlsated by NRW to MapInfo format (TAB) - tracks and location sof sample locations, data and outfalls as well as habitat maps. GIS data used in the planning process are also supplied
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Documents
(
)
Quality
Data quality
- Quality Scope
- Dataset
- Conformity
- Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services
- Explanation
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This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
- Degree
- false
- Lineage
-
The methods employed within this study were largely limited to Phase II sampling that was based on Phase I biotope maps from previous studies. However, if any obviously incorrect biotope boundaries were encountered or if any notable habitats or species were observed during the course of the surveys, then records were appropriately amended. Anthropogenic influences and negative indicators were also recorded where encountered.
A total of 9 littoral mudflat and sandflat sediment biotopes were identified throughout the Severn Estuary SAC and SPA during the course of the study, and their subsequent extent and distribution was mapped using GIS. At each station;
- five replicate 0.01m2 cores were taken to a depth of 15 cm following ISI, Environment Agency and JNCC guidelines. A photograph of the sediment at the station and the general area was also taken. Macrofauna samples were delivered to APEM Ltd for analysis.
- the depth of the Redox Potential Discontinuity (RPD) layer was determined at each station and a second core taken for sediment granulometry. The sediment samples were delivered to the National Laboratory Service (NLS) at Starcross for PSA.
Previous Phase 1 biotope surveys were carried out on behalf of Natural England in 2005. Phase I surveys were also carried out on the Welsh shores between 1996 and 2005 on behalf of CCW. The specific methods used during these surveys are unknown as only the GIS map outputs are available.
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
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NRW Thesaurus
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- aquatic fauna
- aquatic fauna
- sediment infauna
- subtidal sediments
- sediment epifauna
- biota
- Type
- Theme
Citation
- Date (Publication)
- 2025-01-08
Keywords
-
SeaDataNet Parameter Discovery Vocabulary
- Type
- Theme
Citation
- Date (Publication)
- 2024-06-19
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
Constraints
Constraints
Limitations on Public Access and Use
- Restriction type
- Other restrictions
Access Constraints Directive
- Limitations
- no limitations
Access Constraints Text
- Other constraints
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The following data is considered OS derived data and is therefore jointly owned by NRW and the Ordnance Survey. NRW may release, publish or disseminate this data freely; providing recipients are made aware of use restrictions (See general use restrictions).
Use Constraints
- Use constraints type
- Other restrictions
- Other constraints
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© CNC/NRW and © Crown copyright 2012. All rights reserved. Natural Resources Wales, AC0000849444. Third parties seeking to re-use this data require a Licence issued by NRW. It allows re-use, reproduction and dissemination in any format or medium but only for non-commercial purposes, according to the terms and conditions of the Licence. Those seeking commercial re-use require a commercial licence available from the OS.
Metadata
Metadata
- File Identifier
- 4f4c4942-4343-5764-6473-313135353437 XML
- Metadata Language
- English
- Resource type
- Dataset
- Metadata Date
- 2026-03-03T14:43:47.887Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
-
1.0